| Compsopogonophyceae | |
|---|---|
 | |
| Compsopogon sp. | |
Scientific classification  | |
| (unranked): | Archaeplastida |
| Division: | Rhodophyta |
| Subdivision: | Metarhodophytina |
| Class: | Compsopogonophyceae G.W.Saunders & Hommersand, 2004 |
| Orders | |
| Compsopogonophyceae | |
|---|---|
| | |
| Compsopogon sp. | |
| Scientific classification | |
| (unranked): | Archaeplastida |
| Division: | Rhodophyta |
| Subdivision: | Metarhodophytina |
| Class: | Compsopogonophyceae G.W.Saunders & Hommersand, 2004 |
| Orders | |
Algae is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular microalgae, such as Chlorella, Prototheca and the diatoms, to multicellular forms, such as the giant kelp, a large brown alga which may grow up to 50 metres (160 ft) in length. Most are aquatic and autotrophic and lack many of the distinct cell and tissue types, such as stomata, xylem and phloem, which are found in land plants. The largest and most complex marine algae are called seaweeds, while the most complex freshwater forms are the Charophyta, a division of green algae which includes, for example, Spirogyra and stoneworts.
Red tides are a common name for algal blooms, which are large concentrations of aquatic microorganisms, such as protozoans and unicellular algae. The upwelling of nutrients from the sea floor, often following massive storms, provides for the algae and triggers bloom events. Harmful algal blooms can occur worldwide, and natural cycles can vary regionally.
An algal bloom or algae bloom is a rapid increase or accumulation in the population of algae in freshwater or marine water systems, and is often recognized by the discoloration in the water from their pigments. The term algae encompasses many types of aquatic photosynthetic organisms, both macroscopic, multicellular organisms like seaweed and microscopic, unicellular organisms like cyanobacteria. Algal bloom commonly refers to rapid growth of microscopic, unicellular algae, not macroscopic algae. An example of a macroscopic algal bloom is a kelp forest.
The plastid is a membrane-bound organelle found in the cells of plants, algae, and some other eukaryotic organisms. They are considered to be intracelluar endosymbiotic Cyanobacteria. Examples include chloroplasts, chromoplasts, and leucoplasts.
The glaucophytes, also known as glaucocystophytes or glaucocystids, are a small group of freshwater unicellular algae, less common today than they were during the Proterozoic. Only 15 species have been described, but more species are likely to exist. Together with the red algae (Rhodophyta) and the green algae plus land plants, they form the Archaeplastida. However, the relationships among the red algae, green algae and glaucophytes are unclear, in large part due to limited study of the glaucophytes.
The brown algae, comprising the class Phaeophyceae, are a large group of multicellular algae, including many seaweeds located in colder waters within the Northern Hemisphere. Most brown algae live in marine environments, where they play an important role both as food and as a potential habitat. For instance, Macrocystis, a kelp of the order Laminariales, may reach 60 m (200 ft) in length and forms prominent underwater kelp forests. Kelp forests like these contain a high level of biodiversity. Another example is Sargassum, which creates unique floating mats of seaweed in the tropical waters of the Sargasso Sea that serve as the habitats for many species. Many brown algae, such as members of the order Fucales, commonly grow along rocky seashores. Some members of the class, such as kelps, are used by humans as food.
In biology, a biological life cycle is a series of changes in form that an organism undergoes, returning to the starting state. "The concept is closely related to those of the life history, development and ontogeny, but differs from them in stressing renewal." Transitions of form may involve growth, asexual reproduction, or sexual reproduction.
The green algae are a large, informal grouping of algae consisting of the Chlorophyta and Charophyta/Streptophyta, which are now placed in separate divisions, together with the more basal Mesostigmatophyceae, Chlorokybophyceae and Spirotaenia.
Coralline algae are red algae in the order Corallinales. They are characterized by a thallus that is hard because of calcareous deposits contained within the cell walls. The colors of these algae are most typically pink, or some other shade of red, but some species can be purple, yellow, blue, white, or gray-green. Coralline algae play an important role in the ecology of coral reefs. Sea urchins, parrot fish, and limpets and chitons feed on coralline algae. In the temperate Mediterranean Sea, coralline algae are the main builders of a typical algal reef, the Coralligène ("coralligenous"). Many are typically encrusting and rock-like, found in marine waters all over the world. Only one species lives in freshwater. Unattached specimens may form relatively smooth compact balls to warty or fruticose thalli.
Florideophyceae, is a class of red algaeThey were once thought to be the only algae to bear pit connections, but these have since been found in the filamentous stage of the Bangiaceae.They were also thought only to exhibit apical growth, but there are genera known to grow by intercalary growth.Most, but not all, genera have three phases to the life cycle.
The Archaeplastida are a major group of eukaryotes, comprising the red algae (Rhodophyta), the green algae, and the land plants, and some smaller groups such as the glaucophytes. All of the lineages of Archaeplastida have become photoautotrophic, except for the lineage Rhodelphidia, sister to the Rhodophyta, which is still a non-photosynthetic predatorial (eukaryotrophic) flagellate. The Archaeplastida have chloroplasts that are surrounded by two membranes, suggesting that they were acquired directly through a single endosymbiosis event by feeding on a cyanobacterium. All other groups which have chloroplasts, besides the amoeboid Paulinella chromatophora, have chloroplasts surrounded by three or four membranes, suggesting they were acquired secondarily from red or green algae. Unlike red and green algae, glaucophytes have never been involved in secondary endosymbiosis events.
Algae eater, also called an algivore, is a common name for many bottom-dwelling or algae-eating species that feed on algae. Algae eaters are important for the fishkeeping hobby and many are commonly kept by hobbyists.
Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of Rhodophyta (red), Phaeophyta (brown) and Chlorophyta (green) macroalgae. Seaweed species such as kelps provide essential nursery habitat for fisheries and other marine species and thus protect food sources; other species, such as planktonic algae, play a vital role in capturing carbon, producing up to 90% of Earth's oxygen.
Plants are mainly multicellular organisms, predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, plants were treated as one of two kingdoms including all living things that were not animals, and all algae and fungi were treated as plants. However, all current definitions of Plantae exclude the fungi and some algae, as well as the prokaryotes. By one definition, plants form the clade Viridiplantae, a group that includes the flowering plants, conifers and other gymnosperms, ferns and their allies, hornworts, liverworts, mosses, and the green algae, but excludes the red and brown algae.
Red algae, or Rhodophyta, are one of the oldest groups of eukaryotic algae. The Rhodophyta also comprises one of the largest phyla of algae, containing over 7,000 currently recognized species with taxonomic revisions ongoing. The majority of species (6,793) are found in the Florideophyceae (class), and mostly consist of multicellular, marine algae, including many notable seaweeds. Red algae are abundant in marine habitats but are relatively rare in freshwaters. Approximately 5% of the red algae occur in freshwater environments with greater concentrations found in warmer areas. Except for two coastal cave dwelling species in the asexual class Cyanidiophyceae, there are no terrestrial species, which may be due to an evolutionary bottleneck where the last common ancestor lost about 25% of its core genes and much of its evolutionary plasticity.
Stylonematophyceae is a grouping of red algae.
Cyanidiophyceae is a class of unicellular red algae within subdivision Cyanidiophytina, and contain a single plastid, one to three mitochondria, a nucleus, a vacuole and floridean starch. Most are extremophiles inhabiting acid hot springs. The main photosynthetic pigment is C-phycocyanin. Reproduction is asexual by binary fission or formation of endospores.
Porphyridiophyceae is a class of red algae.
Erythropeltidales is a red algae order in the class Compsopogonophyceae.
Marine primary production is the chemical synthesis in the ocean of organic compounds from atmospheric or dissolved carbon dioxide. It principally occurs through the process of photosynthesis, which uses light as its source of energy, but it also occurs through chemosynthesis, which uses the oxidation or reduction of inorganic chemical compounds as its source of energy. Almost all life on Earth relies directly or indirectly on primary production. The organisms responsible for primary production are called primary producers or autotrophs.
Classification of Archaeplastida or Plantae s.l. | |||||||||||||||||||||||||||||||||||||||||||||||||||
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